Alignment method and tools

ABSTRACT

A laser system includes a first cavity to output a laser light along a first path, a first mirror to receive the laser light from the first cavity, and redirect the laser light along a second path that is different than the first path, a beam splitter removably located at a first position on the second path, a beam combiner removably located at a second position on the second path, and an alignment device having first and second alignment features. The first and second alignment features occupy the first position and the second position, respectively, on the second path, when the beam splitter and the beam combiner are removed from the first position and the second position.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application claims the benefit of priority under 35 U.S.C. § 119 to U.S. Provisional Patent Application No. 62/792,524, filed Jan. 15, 2019, which is herein incorporated by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates generally to medical/surgical laser systems, and more particularly, to methods and tools for aligning the medical/surgical laser systems.

BACKGROUND

Medical laser systems are used for a variety of surgical procedures. These procedures may include dusting and/or fragmentation of stones in the kidney, the bladder, and/or the ureter. Medical laser systems are also used to create incisions and to ablate and/or coagulate soft tissues, such as, but not limited to, the prostate. Surgical lasers output from medical laser systems have small diameters, e.g., 2 μm, and are invisible to the naked eye. Thus, it is necessary to use a visible alignment laser beam to align the medical laser system.

Conventional alignment procedures for medical laser systems are time consuming, with alignment generally taking about one to two days to complete. One problem with conventional alignment techniques results from multiple beam spots showing on a mirror during the alignment. Big and weak alignment beam spots on the mirror make it difficult to provide accurate alignment results. Another problem associated with conventional alignment techniques is the inability to determine whether the alignment beam is perpendicular to the mirror surface. If the alignment beam is not perpendicular to the mirror surface, the output laser beam will not be in the same optical axis as the output fiber. The result is the failure of an output from a core fiber after the coarse alignment step at times, requiring additional manipulation of the medical laser system. Yet another problem associated with conventional alignment techniques is the use of a thermal paper during alignment. The use of thermal paper is necessary since the alignment is not accurate, and thermal paper aids in correcting this accuracy. When the output beam is shot through the thermal paper, however, particles are generated which can contaminate and cause damage to the optics.

SUMMARY OF THE DISCLOSURE

In one aspect, a laser system comprises: a first cavity configured to output a laser light along a first path; a first mirror configured to receive the laser light from the first cavity, and redirect the laser light along a second path that is different than the first path; a beam splitter removably located at a first position on the second path; a beam combiner removably located at a second position on the second path; and an alignment device having first and second alignment features, wherein the first and second alignment features are configured to occupy the first position and the second position, respectively, on the second path, when the beam splitter and the beam combiner are removed from the first position and the second position.

The alignment device may further include two extensions spaced apart from one another, wherein the first alignment feature may be a hole in one of the two extensions, and the second alignment feature may be a hole in another of the two extensions.

The alignment device may include a body portion having two slots, and each of the two extensions may extend at least partially through one of the two slots.

The first alignment feature may be equidistant from the body portion as the second alignment feature.

The laser system may further include one or more fastening components and may be configured to secure the beam splitter and the beam combiner into the first position and the second position, respectively, when the laser system is in an operating configuration, and may secure the alignment device so that the first alignment feature and the second alignment feature are in the first position and second position, respectively, when the laser system is in a first calibrating configuration.

The first mirror may be a Galvo mirror adjustable in at least two dimensions.

The laser system may further include a second mirror configured to direct laser energy from the first cavity to the first mirror along a third path that is different from the first path and the second path.

The second mirror may include a film applied to at least one surface of the second mirror.

The laser system may further include a second cavity configured to output a laser light along a fourth path, wherein the fourth path may be different than the first, second, and third paths.

The laser system may further include a third mirror configured to direct laser energy from the second cavity to the first mirror along a fifth path that is different from the fourth path.

The first cavity may include a fourth mirror, and the laser system may further include an alignment laser source, and a fiber may be configured to deliver an alignment laser light from the alignment laser source, through the first alignment feature and the second alignment feature, toward the fourth mirror.

The alignment laser light may be configured to travel through the second alignment feature before travelling through the first alignment feature.

The fiber may have a core diameter from 5 μm to 7 μm.

The fiber may have a numerical aperture from 0.11 to 0.13.

The alignment laser light may be configured to be directed from the first mirror to the fourth mirror.

According to another aspect, a method for aligning a laser system comprises: delivering an alignment beam, through a first alignment feature positioned at a first location and through a second alignment feature positioned at a second location, onto a first mirror contained within a first laser cavity; removing the first alignment feature and the second alignment feature from the laser system; and positioning a beam splitter at the first location, and a beam combiner at the second location.

The first alignment feature and the second alignment feature may both holes positioned within spaced apart extensions of an alignment device.

The laser system may include an adjustable mirror configured to redirect laser light from the first laser cavity, and the method further includes adjusting one or more angles of the adjustable mirror until the alignment beam is centered on the first mirror.

In yet another aspect, a method for aligning a laser system having a first laser cavity comprises: activating a first laser cavity to emit a laser light along a first path toward a first mirror; diverting the emitted light along a second path from the first mirror to a second mirror, wherein the second path is different than the first path; diverting the emitted light along a third path from the second mirror through a first output fiber; measuring a first power of the emitted laser light, at the first output fiber; measuring a second power of a reflection of the emitted laser light between a beam splitter and a beam combiner; determining whether a ratio of the first power to the second power is below a first threshold; and adjusting positions of the first mirror and/or the second mirror until a ratio of the first power to the second power is below a first threshold, while the first output fiber is coupled to the laser system.

The method may further include replacing the first output fiber with a second output fiber having one or more different optical properties than the first output fiber, activating the first laser cavity to emit the laser light along the first path toward the first mirror, diverting the emitted light along the second path from the first mirror to the second mirror, diverting the emitted light along the third path from the second mirror through the second output fiber, measuring the first power of the emitted laser light, at the second output fiber, measuring a third power of the reflection of the emitted laser light, between the beam splitter and the beam combiner, and adjusting positions of the first mirror and/or the second mirror until the ratio of the first power to the second power is below the first threshold, while the second output fiber is coupled to the laser system.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate various exemplary embodiments and together with the description, serve to explain the principles of the disclosed embodiments.

FIG. 1 is a schematic of a medical laser system according to an exemplary embodiment;

FIG. 2 is a perspective view of an alignment device according to an exemplary embodiment;

FIG. 3 is a schematic of the medical laser system of FIG. 1, in a first alignment configuration;

FIG. 4 is a flow chart of a first alignment procedure according to an exemplary embodiment;

FIGS. 5A and 5B are flow charts of a second alignment procedure according to an exemplary embodiment; and

FIG. 6 is a schematic of the medical laser system of FIG. 1, in a second alignment configuration.

DETAILED DESCRIPTION

Both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the features, as claimed. As used herein, the terms “comprises,” “comprising,” “having,” “including,” or other variations thereof, are intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements, but may include other elements not expressly listed or inherent to such a process, method, article, or apparatus. In this disclosure, relative terms, such as, for example, “about,” “substantially,” “generally,” and “approximately” are used to indicate a possible variation of ±10% in a stated value or characteristic.

FIG. 1 illustrates an exemplary embodiment of a medical laser system 1. The medical laser system 1 includes one or more cavities 10 a-10 d, each cavity capable of outputting an output laser beam (or laser light). The output laser beam from each of the cavities 10 a-10 d is directed to a corresponding relay (e.g., first) mirror 20 a-20 d. For example, the output laser beam is output from cavity 10 a to mirror 20 a; for each cavity 10 b to mirror 20 b; from cavity 10 c to 20 c; and from cavity 10 d to 20 d. Each output laser beam is reflected from a respective one of the relay mirrors 20 a-20 d to a Galvo (e.g., second) mirror 30. For example, an output laser beam is reflected from relay mirror 20 a to Galvo mirror 30. The Galvo mirror 30 reflects each output laser beam along a same optical path to a beam splitter 40, a safety shutter 50 (e.g., a shutter), and a beam combiner 60. The beam combiner 60 combines the output laser beams from the one or more cavities 10 a-10 d with an aiming beam from an aiming beam source 65, and passes the combined output laser beam to a coupling lens 70. The aiming beam may be a relatively low power light beam in the visual spectrum that enables an operator to visualize where the output beams from cavities 10 a-10 d will be fired. The coupling lens 70 couples the output laser beam and matches the output laser beam to the output fiber 80, to be transmitted to a delivery location.

To help ensure proper output and to help avoid damage to the medical laser system 1, and injuries to the user and/or the patient, the medical laser system 1 may be calibrated prior to use. The calibration and alignment of the medical laser system 1 may help ensure that the output laser from the one or more cavities 10 a-10 d properly reflects off each mirror and are coupled through coupling lens 70 into the output fiber 80.

According to an exemplary embodiment, an alignment device 90, illustrated in FIG. 2, may be used to assist in the alignment of the medical laser system 1. As shown in FIG. 2, the alignment device 90 includes a body 91 extending along a longitudinal axis 95. Body 91 includes a top surface 91 c, side surfaces 91 d, and a bottom surface (not shown) that opposes top surface 91 c. Body 91 may include two slots 91 a, 91 b provided at opposite ends of the body 91. Slot 91 may extend through each of top surface 91 c and side surfaces 91 d, but not through the bottom surface of body 91. A first insert (or extrusion) 92 a may be provided in the first slot 91 a and a second insert (or extrusion) 92 b may be provided in the second slot 91 b. A fastening mechanism, such as one or more bolts 93, may be used to fasten the first insert 92 a and the second insert 92 b to the body 91. It will be understood that the fastening mechanism is not limited to a bolt or a screw. Indeed, any fastening may be used, such as an adhesive or other fastening mechanism known in the art. Moreover, the body 91 may be provided without the slots 91 a, 91 b and the first insert 92 a and the second insert 92 b may be fastened to a same face of the body 91 by any mechanism known to one of skill in the art.

According to an exemplary embodiment, the first insert 92 a and the second insert 92 b may each include a groove 92 c, 92 d, respectively. The grooves 92 c, 92 d may cooperate with a tab (not shown) in each of the slots 91 a, 91 b to properly align the first insert 92 a and the second insert 92 b in the first slot 91 a and the second slot 91 b, respectively. The tabs may extend into slots 91 a and 91 b, first insert 92 a and second insert 92 b may slide along the respective tabs in a track-type arrangement.

As shown in FIG. 2, a first pinhole 93 a may be provided through the first insert 92 a and a second pinhole 93 b may be provided through the second insert 92 b. The position of the pinholes 93 a, 93 b on each of the protrusions 92 a, 92 b is not limited; however, when the protrusions 92 a, 92 b are attached to the body 91, a laser light should be capable of passing through each of the pinholes 93 a, 93 b. According to an exemplary embodiment, the pinholes 93 a, 93 b are located at a same position on the first insert 92 a and the second insert 92 b, respectively. In one embodiment, first insert 92 a and second insert 92 b may be substantially identical and interchangeable within alignment device 90. When first insert 92 a and second insert 92 b are coupled to body 91, a longitudinal optical axis 96 may extend through substantially similar positions within first insert 92 a and second insert 92 b. Longitudinal optical axis 96 may be substantially parallel to longitudinal axis 95. As will be explained in detail herein, this positioning of the pinholes 93 a, 93 b may allow an alignment laser light to pass from the output of the medical laser system 1 to the Galvo mirror 30, the relay mirrors 20 a-20 d, and the cavities 10 a-10 d to assist in the alignment of the medical laser system 1.

According to an exemplary embodiment, FIG. 3 illustrates that the alignment device 90 may be used in the medical laser system 1 to aid in the alignment thereof, in a first alignment configuration of system 1. As shown in FIG. 3, the alignment device 90 may be positioned such that the first insert 92 a is provided at a location of the beam splitter 40 and the second insert 92 b is provided at a location of the beam combiner 60. According to this exemplary embodiment, the beam splitter 40, the shutter 50, and the beam combiner 60 may be removed prior to inserting the alignment device 90 into the medical laser system 1. Using an alignment device 90 sized such that the first and second protrusions 92 a, 92 b are provided at the location of the beam splitter 40 and the beam combiner 60 may allow the user to attach the alignment device 90 in the medical laser system 1 using the same fastening elements (not shown) as used to position the beam splitter 40 and the beam combiner 60 in the medical laser system 1. It will be understood, however, that fastening the alignment device 90 is not limited and any attachment mechanism, such as thumb screws, clamps, or any other fastening mechanism not to one of ordinary skill in the art, may be used to removably fasten the alignment device 90 in the medical laser system 1 during alignment thereof. It will be understood that, after alignment of the medical laser system 1, the alignment device 90 may be removed from the medical laser system 1, and the beam splitter 40, the shutter 50, and the beam combiner 60 may be replaced and fastened in the medical laser system 1.

According to an exemplary embodiment, the relay mirrors 20 a-20 d may each be provided with a coating to increase the brightness of an alignment beam (alignment laser light) on an output coupling (OC) mirror 11 a-11 d in each of the cavities 10 a-10 d. The coating may provide a reflection of greater than approximately 50% at an alignment laser wavelength. Further, a thin film may be applied to enhance the brightness of the alignment beam on the OC mirrors 11 a-11 d. According to an exemplary embodiment, the coating may provide a reflectivity from the OC mirrors 11 a-11 d of greater than approximately 50%, when providing an alignment laser beam at a visible wavelength range, and an incident angle of the OC mirrors 11 a-11 d at 0°. In response, a single alignment beam having a size approximately 1.5 mm to 2.5 mm, or about 2 mm, in diameter may be obtained on each of the OC mirrors 11 a-11 d, which may simplify the alignment procedure and help ensure a more accurate alignment.

With continued reference to FIG. 3, an alignment beam source 100 may be used to provide an alignment laser beam to align the medical laser system 1. The alignment beam source 100 may include a semiconductor laser diode and a single mode optical fiber (alignment laser fiber) 101 having a core diameter of 6 μm and NA=0.12. The alignment beam source 100 according to the exemplary embodiment may provide a beam diameter of about 2.5 mm to 3.5 mm, or approximately 3 mm on the Galvo mirror 30, and a beam diameter of about 2.5 mm to 3.5 mm, or approximately 2 mm on each of the OC mirrors 11 a-11 d, thereby improving the alignment accuracy. It will be understood that the alignment beam source 100 is not limited to these parameters and may change according to the requirements of the laser medical system 1.

As further illustrated in FIG. 3, alignment laser fiber 101 of the alignment beam source 100 is connected to an output 1 a of the medical laser system 1 and the alignment beam source 100. A simplified illustration of the medical laser system 1 and the alignment beam source 100 is shown in FIG. 6. The output 1 a of the medical laser system 1 may be an SMA fiber connector provided after the coupling lens 70 (relative to the beam path). The output 1 a is not limited to the SMA fiber connector and may be any connector suitable for outputting and receiving a laser energy.

In a second alignment configuration of system 1, shown in FIG. 6, first core fiber (test fiber) 120, which may have a diameter greater than 550 μm, may be attached to the output 1 a using, for example, an SMG connector. A second core fiber 130 having a diameter of 365 μm may also be attached to the output 1 a using the SMG connector. In addition, a first power meter 110 a may be attached to an end of the first core fiber 120 opposite the end connected to the output 1 a, as shown in FIG. 6. The optical power measured at a distal end of the fiber using first power meter 110 a is measured as P1. A second power meter 110 b may be provided between the beam splitter 40 and the beam combiner 60, as illustrated in FIG. 6. The optical power measured at a location proximal of the fiber is measured by the second power meter as P2. The fiber coupling efficiency is defined as P1/P2 multiplied by 100%.

The medical laser system 1 provides a reflection of the alignment laser beam from each of the OC mirrors 11 a-11 d when an incident angle of the OC mirrors 11 a-11 d is set to 0°. This orientation may provide a reflection of 35%-45%, and in some cases approximately 40%, of the alignment laser beam from the OC mirrors 11 a-11 d. According to an exemplary embodiment, the wavelength of the alignment laser beam may be about 625 nm to 675 nm, or 640 nm to 660 nm, and in some embodiments approximately 650 nm. It will be understood that the wavelength of the alignment laser beam is not limited thereto and any visible wavelength suitable for use for an alignment laser beam may be used.

A method of aligning the medical laser system 1 according to an exemplary embodiment will now be described. At the outset, coordinates of various elements of the medical laser system are described herein, reference for which should be made to FIG. 3.

FIG. 4 illustrates a flow chart of a first (e.g., initial) alignment procedure according to an exemplary embodiment. As shown in Step S1, the alignment device 90 is inserted into the medical laser system 1 between the Galvo mirror 30 and the coupling lens 70 (after beam splitter 40 and beam combiner 60 have been removed). As provided above, the alignment device 90 may be removably attached to the medical laser system 1 using the same attachment mechanism as used for attaching the beam splitter 40 and the beam combiner 60. Further, the first insert 92 a may be placed in a same position as the attachment location for the beam splitter 40 and the second insert 92 b may be placed in a same position as the attachment location for the beam combiner 60. For ease of understanding, the discussion will refer to the first insert 92 a as being adjacent the Galvo mirror 30 and the second insert 92 b as being adjacent the coupling lens 70. However, the medical laser system 1 is not limited to this orientation.

Once the alignment device 90 is inserted into the medical laser system 1, the alignment laser fiber 101 of the alignment beam source 100 is connected to the output 1 a of the medical laser system 1 and the alignment beam source 100 is activated, as shown in Step S2.

In Step S3, the coupling lens 70 illustrated in FIG. 3 is adjusted in the X- and Y-axes to direct the alignment laser beam through the pinholes 93 a, 93 b of the first insert 92 a and the second insert 92 b, respectively.

In Step S4, the Galvo mirror 30 illustrated in FIG. 3 has an angle 13=0° and the angle θ of the Galvo mirror 30 is adjusted to reflect the laser alignment beam from the Galvo mirror 30 back into at least pinhole 93 a of the first insert 92 a. For reference purposes, a z-axis lies along the output path of the output beam; a y-axis is perpendicular to the z-axis and extends in a vertical direction in FIG. 1, e.g., perpendicular to a base plate (not shown) on which Galvo mirror 30 and relay mirrors 20 a-d are disposed; and a x-axis is perpendicular to both the z-axis and the y-axis and is normal to FIG. 1. The angle β may be defined as a rotation angle along a plane defined by the x- and z-axes, e.g., a rotation of Galvo mirror 30 and/or relay mirrors 20 a-d in a horizontal direction, whereas the angle θ may be defined as a rotation angle along a plane defined by the y- and z-axes, e.g. a rotation of Galvo mirror 30 and/or relay mirrors 20 a-d in a vertical direction.

Once the laser alignment beam is reflected back into at least pinhole 93 a of the first insert 92 a, Step S5 is performed. In Step S5, the angle β of the Galvo mirror 30 and the angle θ of a first relay mirror 20 a are adjusted to direct the laser alignment beam onto the center of a first OC mirror 11 a of a first cavity 10 a.

In Step S6, a lens paper is placed over the pinhole 93 a on a side of the first insert 92 a facing the first OC mirror 11 a. The lens paper is used to observe the laser alignment beam reflected from the first OC mirror 11 a around the pinhole 93 a of the alignment device 90. During Step S6, the angle β of the first relay mirror 20 a and the angle θ of the cavity 10 a are adjusted until the laser alignment beam is reflected back through the first pinhole 93 a of the alignment device 90.

It is possible that, after Steps S5 and S6, the laser alignment beam is not on the center of the first OC mirror 11 a and the laser alignment beam reflected from the first OC mirror 11 a is not reflected through the first pinhole 93 a. In the event that this occurs, Step S7 includes repeating Steps S5 and S6 until the laser alignment beam is on the center of the first OC mirror 11 a and the laser alignment beam reflected from the first OC mirror 11 a is reflected through the first pinhole 93 a. A lens paper is placed in front of OC mirror 11 a to determine if the alignment beam in on the center of the OC mirror 11 a.

Once the laser alignment beam is on the center, or at least substantially on the center, of the first OC mirror 11 a and the laser alignment beam reflected from the first OC mirror 11 a is reflected through the first pinhole 93 a, it is determined in Step S8 whether all cavities 10 a-10 d have been aligned. If not, in Step S9 the next cavity is selected and Steps S5 to S7 are repeated for each cavity 10 b-10 d using corresponding relay mirrors 20 b-20 d and the Galvo mirror 30.

Once the first alignment procedure is completed, a second (e.g., final) alignment procedure is performed, as illustrated in FIGS. 5A and 5B.

As illustrated in FIGS. 5A and 5B, the alignment beam source 100 and the alignment device 90 are removed from the medical laser system 1 in Step S10.

In Step S11, the beam splitter 40 and the beam combiner 60 are placed into the medical laser system 1 in the positions shown in FIG. 6. The beam splitter 40 and the beam combiner 60 may be attached to the medical laser system 1 using the same or different fastening mechanisms as those used to removably fasten the alignment device 90.

In Step S12, the first core fiber 120 may be attached to the output 1 a using an SMG connector. In addition, the first power meter 110 a may be attached to an end of the first core fiber 120 opposite the end connected to the output 1 a. A second power meter 110 b may be provided between the beam splitter 40 and the beam combiner 60.

During Step S13, the first cavity 10 a may be powered on and the pulse energy is gradually increased from 0.2 J to 0.5 J. During this time, a power P1 is measured at the first power meter 110 a and a power P2 is measured at the second power meter 110 b at different pulse energies. The pulse energies may be preset and the number of pulse energies at which P1 and P2 measurements are performed is not limited.

In Step S14, it is determined whether P1/P2 is greater than or equal to a first threshold value (e.g., 80%). If P1/P2 is less than 80%, Step S15 is performed, in which the angle β of the Galvo mirror 30 and the angle θ of the relay mirror 20 a is adjusted. The adjustment of the Galvo mirror 30 and the relay mirror 20 a is iterative until the ratio P1/P2 is greater than or equal to the first threshold value. After Step S15 is performed, Step S13 is repeated to determine whether P1/P2 is greater than or equal to the first threshold value. According to some embodiments, the first threshold may be determined by a specification of medical laser system 1, e.g., a tolerance of the system. Additionally or alternatively, the first threshold fiber coupling efficiency may account for transmission loss of the beam combiner, the fiber coupling lens 70, and a blast shield; a reflection lows of two surfaces of the fiber; absorption by the fiber and scattering loss; and/or a coupling loss.

Once it is determined that P1/P2 is greater than or equal to the first threshold value, Step S16 determines if the power of each cavity has been tested. If the power of each cavity has not been measured, the cavity is changed in Step S17. Steps S13-S15 are thus performed for each of cavities 10 b-10 d. While the medical laser system 1 described herein includes four cavities 10 a-10 d, the medical laser system 1 is not limited thereto. Accordingly, Steps S13-S15 should be performed for each cavity of the medical laser system 1.

After Steps S13-S15 are completed for each of cavities 10 a-10 d, Step S18 is performed, which determined if a second core fiber (test fiber) 130 has been used. If the second core fiber 130 has not yet been used, the first core fiber 120, which may have a diameter of 910 μm, is replaced with a second core fiber 130 having a diameter of 365 μm in Step 19. Steps S13-S17 are repeated using the second core fiber 130. The second core fiber 130 represents a fiber which may be used in medical laser system 1, since a 100 watt laser may be coupled into a fiber having a diameter of 365 μm. Thus, this tests to ensure proper orientation when using a fiber specified for use with medical laser system 1.

After the power of each of cavities 10 a-10 d has been measured using the first core fiber 120 and the second core fiber 130, Step S20 is performed, during which the second power meter 110 b is removed from the medical laser system 1.

Step S21 includes measuring the power P1 of the pulse from the first cavity 10 a using the first power meter 110 a using the first core fiber 120 and the second core fiber 130. The first cavity 10 a is set to produce a beam having an energy of up to about 2 J per pulse at about 25-75 Hz, or about 50 Hz in some embodiments. If the difference in output power P1 at the first power meter 110 a between the first core fiber 120 and the second core fiber 130 is less than a second threshold value (e.g. 5%) in Step S22, Step S21 is complete. If the difference in the output power P1 is greater than the second threshold value, Step S25 is performed, in which the method proceeds back to Step S15 such that Galvo mirror 30 and relay mirror 20 a are readjusted.

In Step S23, it is determined whether the power P1 of each of cavities 10 a-10 d has been measured. If not, the cavity is changed in S24 and Steps S21 and S22 are repeated for each of the cavities 10 b-10 d.

Step S26 includes measuring the power P1 of the first cavity 10 a using the first power meter 110 a using the first core fiber 120 and a third core fiber (test fiber) 140 having a diameter of 242 μm and NA=0.28. The first cavity 10 a is set to produce a beam having an energy of 0.5 J per pulse at 80 Hz. If the difference in output power P1 at the first power meter 110 a between the first core fiber 120 and the third core fiber 140 is less than a third threshold value (e.g., 10%) in Step S27, Step S26 is complete. If the difference in the output power P1 in Step S26 is greater than the third threshold value, Step S30 is performed, in which the method proceeds back to Step S15 such that Galvo mirror 30 and relay mirror 20 a are readjusted.

In Step S28, it is determined whether the power P1 of each of cavities 10 a-10 d has been measured. If not, the cavity is changed in S29 and Steps S26 and S27 are repeated for each of the cavities 10 b-10 d.

According to an exemplary embodiment, the alignment method described herein may be performed using two phases, thereby eliminating the need for a third phase. According to an embodiment, the system can be provided without a light emitting diode (LED), since an LED produces a beam that is insufficient to use in aligning the medical laser system. According to another embodiment, the system may be used without a thermal paper, since the alignment beam source may be seen directly on an insert. According to yet another exemplary embodiment, the alignment system and method described herein may be used without the need for a special beam splitter, e.g., a beam splitter that reflects more light to a power meter than coupled into a fiber at the output of the system. Moreover, the alignment system and method described herein may be used without the need for thermal paper.

The alignment procedure described above may significantly reduce the alignment time of the medical laser system 1. Due to the smaller and brighter alignment beam from the alignment beam source 100 and the alignment device 90, the alignment procedure described herein is more accurate, simpler, and less time consuming than conventional techniques. The reflection beam from the OC mirrors 11 a-11 d through the first pinhole 93 a is advantageous in that it ensures that the output laser beam is on the same optical axis of the output fiber 80 attached to the output 1 a of the medical laser system 1. Accordingly, after the alignment using the alignment beam source 100, few if any fine-alignments of the medical laser system 1 are required to finalize the alignment. The alignment procedures of the present disclosure also may help technicians and operators service laser systems in the field, without requiring the systems to be sent off-site for service.

It will be understood that reference is made to a number of cavities and/or mirrors in the medical laser system 1. It will be understood that the devices are not limited to this number and may change according to the requirement of the medical laser system 1. Further, while reference is made to a medical/surgical laser system, the alignment technique described herein is not limited to a medical/surgical laser system and may be used with any laser system.

It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed device without departing from the scope of the disclosure. Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims. 

What is claimed is:
 1. A laser system, comprising: a first cavity configured to output a laser light along a first path; a first mirror configured to receive the laser light from the first cavity, and redirect the laser light along a second path that is different than the first path; a beam splitter removably located at a first position on the second path; a beam combiner removably located at a second position on the second path; and an alignment device having first and second alignment features, wherein the first and second alignment features are configured to occupy the first position and the second position, respectively, on the second path, when the beam splitter and the beam combiner are removed from the first position and the second position.
 2. The laser system according to claim 1, wherein the alignment device includes two extensions spaced apart from one another, wherein the first alignment feature is a hole in one of the two extensions, and the second alignment feature is a hole in another of the two extensions.
 3. The laser system according to claim 2, wherein: the alignment device includes a body portion having two slots; and each of the two extensions extends at least partially through one of the two slots.
 4. The laser system according to claim 3, wherein the first alignment feature is equidistant from the body portion as the second alignment feature.
 5. The laser system according to claim 1, further including one or more fastening components configured to: secure the beam splitter and the beam combiner into the first position and the second position, respectively, when the laser system is in an operating configuration; and secure the alignment device so that the first alignment feature and the second alignment feature are in the first position and second position, respectively, when the laser system is in a first calibrating configuration.
 6. The laser system according to claim 1, wherein the first mirror is a Galvo mirror adjustable in at least two dimensions.
 7. The laser system according to claim 1, further including a second mirror configured to direct laser energy from the first cavity to the first mirror along a third path that is different from the first path and the second path.
 8. The laser system according to claim 1, wherein the second mirror includes a film applied to at least one surface of the second mirror.
 9. The laser system according to claim 1, further including a second cavity configured to output a laser light along a fourth path, wherein the fourth path is different than the first, second, and third paths.
 10. The laser system according to claim 9, further including a third mirror configured to direct laser energy from the second cavity to the first mirror along a fifth path that is different from the fourth path.
 11. The laser system according to claim 1, wherein: the first cavity includes a fourth mirror; and the laser system further includes an alignment laser source, and a fiber configured to deliver an alignment laser light from the alignment laser source, through the first alignment feature and the second alignment feature, toward the fourth mirror.
 12. The laser system according to claim 11, wherein the alignment laser light is configured to travel through the second alignment feature before travelling through the first alignment feature.
 13. The laser system according to claim 11, wherein the fiber has a core diameter from 5 μm to 7 μm.
 14. The laser system according to claim 11, wherein the fiber has a numerical aperture from 0.11 to 0.13.
 15. The laser system according to claim 1, wherein the alignment laser light is configured to be directed from the first mirror to the fourth mirror.
 16. A method for aligning a laser system, the method comprising: delivering an alignment beam, through a first alignment feature positioned at a first location and through a second alignment feature positioned at a second location, onto a first mirror contained within a first laser cavity; removing the first alignment feature and the second alignment feature from the laser system; and positioning a beam splitter at the first location, and a beam combiner at the second location.
 17. The method according to claim 16, wherein the first alignment feature and the second alignment feature are both holes positioned within spaced apart extensions of an alignment device.
 18. The method according to claim 16, wherein the laser system includes an adjustable mirror configured to redirect laser light from the first laser cavity, and the method further includes adjusting one or more angles of the adjustable mirror until the alignment beam is centered on the first mirror.
 19. A method for aligning a laser system having a first laser cavity, the method comprising: activating a first laser cavity to emit a laser light along a first path toward a first mirror; diverting the emitted light along a second path from the first mirror to a second mirror, wherein the second path is different than the first path; diverting the emitted light along a third path from the second mirror through a first output fiber; measuring a first power of the emitted laser light, at the first output fiber; measuring a second power of a reflection of the emitted laser light between a beam splitter and a beam combiner; determining whether a ratio of the first power to the second power is below a first threshold; and adjusting positions of the first mirror and/or the second mirror until a ratio of the first power to the second power is below a first threshold, while the first output fiber is coupled to the laser system.
 20. The method according to claim 19, further including: replacing the first output fiber with a second output fiber having one or more different optical properties than the first output fiber; and activating the first laser cavity to emit the laser light along the first path toward the first mirror; diverting the emitted light along the second path from the first mirror to the second mirror; diverting the emitted light along the third path from the second mirror through the second output fiber; measuring the first power of the emitted laser light, at the second output fiber; measuring a third power of the reflection of the emitted laser light, between the beam splitter and the beam combiner; and adjusting positions of the first mirror and/or the second mirror until the ratio of the first power to the second power is below the first threshold, while the second output fiber is coupled to the laser system. 